macOS: real .plugin bundle packaging, libobs @rpath fixup, hard-fail CI check

Closes the "macOS packaging gap" documented in README.md: CI built a real
adapter module on macOS but staged it as a bare streamer-tools-camera.so,
which OBS.app cannot load (it needs a <name>.plugin bundle), and otool -L
showed the libobs dependency as the relative path
libobs/libobs.framework/Versions/A/libobs instead of an @rpath reference.

cmake/macos/helpers.cmake adapts (not vendors as-is) obs-plugintemplate's
cmake/macos/helpers.cmake: upstream builds the bundle almost entirely
through XCODE_ATTRIBUTE_* properties and its own CI drives that with
`xcodebuild -project <name>.xcodeproj`, but this project's home-mac runner
has only the Command Line Tools, not Xcode.app (already established by
buildspec_common.cmake's CI-iteration-1 comment), and the whole project
builds with Ninja end to end. So this reimplements the same outcome --
Contents/MacOS, Contents/Resources, a real Info.plist -- with CMake's own
generator-agnostic BUNDLE/BUNDLE_EXTENSION/MACOSX_BUNDLE_INFO_PLIST/
MACOSX_PACKAGE_LOCATION target properties (verified working under Ninja via
a dry-run configure with APPLE spoofed), and does by hand what upstream gets
from Xcode's embed/codesign build phases:
  - copies obs-adapter/data/** into Contents/Resources/**, since OBS's
    AddExtraModulePaths() (UI/window-basic-main.cpp) passes
    Contents/Resources as a macOS module's *data path* -- not a sibling
    data/ the way Linux/Windows work -- so the locale ini has to land at
    Contents/Resources/locale/en-US.ini for OBS_MODULE_USE_DEFAULT_LOCALE
    to find it
  - copies the LiveKit runtime dylibs into Contents/Frameworks
  - fixes up the libobs dependency: cmake/macos/fixup-libobs-rpath.sh
    rewrites the relative install name the from-source libobs build records
    to @rpath/libobs.framework/Versions/A/libobs (LiveKit's own dylibs
    already record @rpath references, confirmed in prior CI otool -L
    output, so only libobs needs the rewrite)
  - gives the plugin binary two LC_RPATH entries via INSTALL_RPATH:
    @loader_path/../Frameworks (this bundle's own Frameworks, for LiveKit)
    and @executable_path/../Frameworks (OBS.app/Contents/Frameworks, for
    libobs.framework -- @executable_path is always relative to the host
    process's main executable, not this dlopen'd bundle)

obs-adapter/CMakeLists.txt: calls stplugin_macos_finalize_bundle() before
staging, and corrects the staged layout for macOS -- OBS's module search
wants the whole <name>.plugin dropped directly into .../obs-studio/plugins/,
not nested under a bin/ subdirectory the way Linux/Windows are, so
build/package/ now holds the bundle at its own top level on macOS instead of
build/package/bin/<name>.plugin.

.gitea/scripts/macos-build.sh (this project's macOS steps were factored out
of build.yml into this shared script, used by both build.yml and
release.yml, in a concurrent commit -- rebased onto that): the "Show what
was built" section now hard-fails unless a real .plugin bundle (with
Info.plist, bundled LiveKit dylibs, and locale data) was produced, the
libobs dependency resolves via @rpath rather than the old relative path,
and both LC_RPATH entries are present -- closing the same
false-positive-green gap this project's Windows find_package(libobs)
incident just exposed, which this check previously did not cover (it only
checked for a bare .so). release.yml's macOS packaging step already globs
for any `*.plugin` under build/ (added in the concurrent commit,
anticipating this fix), so it picks up the new layout with no change
needed.

Verified: Linux configure/build/ctest (STPLUGIN_BOOTSTRAP_OBS=OFF) still
passes 6/6, unaffected -- the new macOS CMake logic is fully guarded by
if(APPLE). The bundle/Info.plist/Resources-mapping logic itself was dry-run
verified by configuring a throwaway CMake project with APPLE spoofed to
TRUE, confirming buildspec.json values substitute correctly into Info.plist
and obs-adapter/data/locale/en-US.ini maps to Resources/locale/en-US.ini.
Not verified: an actual macOS build/link/otool pass, or loading the result
in real OBS.app -- this is a Linux sandbox with no way to do either: this
commit is going to the home-mac CI runner to get that verification next.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RL8abRmgFXkVASHkkqiJbE

obs-adapter/CMakeLists.txt

@@ -42,18 +42,32 @@ set_target_properties(${STPLUGIN_PROJECT_NAME} PROPERTIES
 # straight copy of the built module (see the staging step below), so the
 # build-tree RPATH must never be baked in -- it would work on the build
 # machine and nowhere else.
-if(APPLE)
-    set_target_properties(${STPLUGIN_PROJECT_NAME} PROPERTIES
-        BUILD_WITH_INSTALL_RPATH ON
-        INSTALL_RPATH "@loader_path"
-    )
-elseif(UNIX)
+#
+# APPLE's rpath (and its whole bundle shape) is handled by
+# stplugin_macos_finalize_bundle() below instead -- a bundle needs two
+# rpaths (its own Contents/Frameworks *and* the host OBS.app's
+# Contents/Frameworks for libobs.framework), not the single flat
+# "@loader_path" this used to set back when macOS staged a bare .so. See
+# cmake/macos/helpers.cmake.
+if(UNIX AND NOT APPLE)
     set_target_properties(${STPLUGIN_PROJECT_NAME} PROPERTIES
         BUILD_WITH_INSTALL_RPATH ON
         INSTALL_RPATH "$ORIGIN"
     )
 endif()
 
+# --- macOS: turn the flat MODULE library into a real OBS.app-loadable
+# <name>.plugin bundle (Contents/MacOS, Contents/Resources, Info.plist,
+# Contents/Frameworks for the bundled LiveKit dylibs, and the libobs
+# @rpath fixup). Closes the "macOS packaging gap" in README.md. Must run
+# before the staging step below, which copies the finished bundle directory
+# -- add_custom_command(POST_BUILD) commands attached to the same target run
+# in the order they were registered.
+if(APPLE)
+    include(helpers)
+    stplugin_macos_finalize_bundle(${STPLUGIN_PROJECT_NAME})
+endif()
+
 # --- staged, runnable layout ------------------------------------------------
 # Everything a human needs to copy into an OBS plugin directory ends up under
 # build/package/, with the LiveKit shared libraries and the licence files
@@ -68,27 +82,52 @@ set(STPLUGIN_PACKAGE_DIR "${CMAKE_BINARY_DIR}/package")
 #   <config>/obs-studio/plugins/<name>/data/
 # so staging into bin/64bit makes build/package/ a straight drop-in.
 #
-# macOS is NOT this shape -- there OBS looks for a
-# <name>.plugin/Contents/MacOS bundle -- and this build does not produce one.
-# See the macOS packaging gap in README.md; the flat bin/ here is honest
-# about being unfinished rather than pretending to be installable.
+# macOS is a COMPLETELY different shape, not just "bin without 64bit": the
+# same AddExtraModulePaths() passes GetConfigPath(...,
+# "obs-studio/plugins/%module%.plugin") as the base, then
+# obs_add_module_path(base + "/Contents/MacOS", base + "/Contents/Resources")
+# -- i.e. OBS wants the ENTIRE <name>.plugin bundle dropped directly into
+# .../obs-studio/plugins/, not nested under a bin/ subdirectory the way
+# Linux/Windows are. So build/package/ on macOS holds the bundle itself at
+# its top level (build/package/<name>.plugin), not build/package/bin/....
+# stplugin_macos_finalize_bundle() (cmake/macos/helpers.cmake) makes
+# ${STPLUGIN_PROJECT_NAME} an actual BUNDLE target for APPLE and also copies
+# obs-adapter/data/** into Contents/Resources/** -- see that file for why
+# Contents/Resources (not a sibling data/) is where OBS looks for this
+# module's data on macOS.
 if(APPLE)
-    set(STPLUGIN_PACKAGE_BIN_DIR "${STPLUGIN_PACKAGE_DIR}/bin")
+    add_custom_command(TARGET ${STPLUGIN_PROJECT_NAME} POST_BUILD
+        COMMAND ${CMAKE_COMMAND} -E make_directory "${STPLUGIN_PACKAGE_DIR}"
+        COMMAND ${CMAKE_COMMAND} -E rm -rf "${STPLUGIN_PACKAGE_DIR}/${STPLUGIN_PROJECT_NAME}.plugin"
+        COMMAND ${CMAKE_COMMAND} -E copy_directory
+            "$<TARGET_BUNDLE_DIR:${STPLUGIN_PROJECT_NAME}>"
+            "${STPLUGIN_PACKAGE_DIR}/${STPLUGIN_PROJECT_NAME}.plugin"
+        COMMENT "Staging the ${STPLUGIN_PROJECT_NAME}.plugin bundle into ${STPLUGIN_PACKAGE_DIR}"
+        VERBATIM
+    )
 else()
     set(STPLUGIN_PACKAGE_BIN_DIR "${STPLUGIN_PACKAGE_DIR}/bin/64bit")
+    add_custom_command(TARGET ${STPLUGIN_PROJECT_NAME} POST_BUILD
+        COMMAND ${CMAKE_COMMAND} -E make_directory "${STPLUGIN_PACKAGE_BIN_DIR}"
+        COMMAND ${CMAKE_COMMAND} -E copy "$<TARGET_FILE:${STPLUGIN_PROJECT_NAME}>" "${STPLUGIN_PACKAGE_BIN_DIR}/"
+        COMMAND ${CMAKE_COMMAND} -E copy ${LIVEKIT_SDK_RUNTIME_LIBS} "${STPLUGIN_PACKAGE_BIN_DIR}/"
+        COMMAND ${CMAKE_COMMAND} -E make_directory "${STPLUGIN_PACKAGE_DIR}/data/locale"
+        COMMAND ${CMAKE_COMMAND} -E copy
+            "${CMAKE_CURRENT_SOURCE_DIR}/data/locale/en-US.ini"
+            "${STPLUGIN_PACKAGE_DIR}/data/locale/"
+        COMMENT "Staging plugin + LiveKit runtime libraries + locale data into ${STPLUGIN_PACKAGE_DIR}"
+        VERBATIM
+    )
 endif()
 
+# Licence files: not something OBS's module loader looks for at all (unlike
+# the locale data above), so these always land in the same top-level spot
+# regardless of platform -- next to the bundle on macOS, next to bin/ on
+# Linux/Windows. Redistributing LiveKit's prebuilt binaries means shipping
+# their licence and notice with them; see third_party/livekit/README.md,
+# including what upstream does NOT ship, which is an open question, not a
+# solved one.
 add_custom_command(TARGET ${STPLUGIN_PROJECT_NAME} POST_BUILD
-    COMMAND ${CMAKE_COMMAND} -E make_directory "${STPLUGIN_PACKAGE_BIN_DIR}"
-    COMMAND ${CMAKE_COMMAND} -E copy "$<TARGET_FILE:${STPLUGIN_PROJECT_NAME}>" "${STPLUGIN_PACKAGE_BIN_DIR}/"
-    COMMAND ${CMAKE_COMMAND} -E copy ${LIVEKIT_SDK_RUNTIME_LIBS} "${STPLUGIN_PACKAGE_BIN_DIR}/"
-    COMMAND ${CMAKE_COMMAND} -E make_directory "${STPLUGIN_PACKAGE_DIR}/data/locale"
-    COMMAND ${CMAKE_COMMAND} -E copy
-        "${CMAKE_CURRENT_SOURCE_DIR}/data/locale/en-US.ini"
-        "${STPLUGIN_PACKAGE_DIR}/data/locale/"
-    # Redistributing LiveKit's prebuilt binaries means shipping their licence
-    # and notice with them. See third_party/livekit/README.md -- including
-    # what upstream does NOT ship, which is an open question, not a solved one.
     COMMAND ${CMAKE_COMMAND} -E make_directory "${STPLUGIN_PACKAGE_DIR}/licenses/livekit"
     COMMAND ${CMAKE_COMMAND} -E copy
         "${CMAKE_SOURCE_DIR}/third_party/livekit/LICENSE"
@@ -98,6 +137,6 @@ add_custom_command(TARGET ${STPLUGIN_PROJECT_NAME} POST_BUILD
     COMMAND ${CMAKE_COMMAND} -E copy
         "${CMAKE_SOURCE_DIR}/LICENSE"
         "${STPLUGIN_PACKAGE_DIR}/licenses/"
-    COMMENT "Staging plugin + LiveKit runtime libraries + licences into ${STPLUGIN_PACKAGE_DIR}"
+    COMMENT "Staging licences into ${STPLUGIN_PACKAGE_DIR}"
     VERBATIM
 )